sphere thread in Yarp using c++: how can I resolve the "Reply from iCubSim: [fail] "could not set index" error"?

[bionicsgirl]

Hi there!
I have to create a thread of a sphere that moves first on the right to reach the end of a radius in 2 seconds of time and then move in circle with a frequency of 0.2 Hz in Yarp and iCub simulator programming in C++.
This is my code and, after initializing the sphere correctly i get this error: Reply from iCubSim: [fail] "could not set index"
How can i resolve this?
Thank you in advance!

#include <iostream>
#include <yarp/os/all.h>
#include <yarp/sig/all.h>
#include <yarp/dev/all.h>

using namespace yarp::os;
using namespace yarp::dev;
using namespace yarp::sig;
using namespace std;

class SphereThread: public PeriodicThread {

	public: 

             SphereThread(double p):PeriodicThread(p){
			
			bool ok  = sphere_port.open("/sphere-client");
				if (!ok) {
					std::cerr << "Failed to open port" << std::endl;
					return;
				}
			// Connect the client to the RPC Server of iCub_SIM
			yarp.connect("/sphere-client", "/icubSim/world");
			}
		
		

	protected:
    
    	    bool threadInit(){
			
			
			req.addString("world");
			req.addString("mk");
			req.addString("ssph");
			req.addFloat64(0.04);
			req.addFloat64(0.02);
			req.addFloat64(0.9);
			req.addFloat64(0.8);
			req.addFloat64(1);
			req.addFloat64(0);
			req.addFloat64(0);  
			sphere_port.write(req,reply);
			cout << "Reply from iCubSim: " << reply.toString() << endl;
   	    	        return true;
			
			
   	    }

		void run() {
			double initial_time = Time::now();
				while (Time::now() - initial_time < 2.0){
					double t = Time::now() - initial_time;
					double xPos = 0.02 + 0.4*(t/2.0);
					double yPos = 0.9;
					setPosition(xPos, yPos);
				}
				while (Time::now() < initial_time+2) {

					double t = Time::now() - initial_time;
					double theta = 2.0*M_PI*0.2*t;
					double xPos = 0.02 + 0.4*cos(theta);
					double yPos = 0.9  + 0.4*sin(theta);
					setPosition(xPos, yPos);
				
				}


			}
			
		
			
		
		void threadRelease() {
			yarp.disconnect("/sphere-client", "/icubSim/world");
    		        sphere_port.close();
			cout << "Done, goodbye from myThread." << endl;
		}
	
    private:

		Network yarp;  //initialize the network
    	        RpcClient sphere_port;  // create rpc client for the sphere
		Bottle req, reply;
		
		
		void setPosition(double x, double y){
			req.clear();
			req.addString("world");
			req.addString("set");
			req.addString("ssph");
			req.addFloat64(1);
			req.addFloat64(x);
			req.addFloat64(y);
			req.addFloat64(0.8);
			sphere_port.write(req, reply);
			cout << "Reply from iCubSim: " << reply.toString() << endl;
		}
        

};


int main(int argc, char *argv[]) {

    Network yarp;
    srand(time(NULL));
    SphereThread mt(0.2/0.1);
    mt.start();
    
    Time::delay(20);
    mt.stop();

    return 0;

};

[pattacini]

Hi @bionicsgirl

At first sight, I think that the main problem is due to the double definition of Network yarp. Just stick to the definition in main and get rid of the definition inside the class.

You can connect and disconnect ports inside the main, more profitably, or even outside your program by resorting to the YARP command-line suite.

[bionicsgirl]

I guess the problem was that I initialized xPos and yPos as double, when the Bottle takes as message Float64.

[pattacini]

This is quite unlikely to be the problem as double are merely float with 64-bit of storage.
Also, please, don't close the discussion yourself.